Micro-electro-mechanical-systems (MEMS) technology is used in some digital cameras to fabricate moving mechanical structures with less than 1 micron tolerance. This technology provides alignment accuracies required for high performance digital cameras. In particular embodiments, a MEMS fabricated capacitor includes two conducting plates whose spacing varies as the potential between two plates is changed which in turn adjusts the capacitance of the MEMS capacitor. If the optical lens of a camera is connected to one plate of MEMS capacitor and the other plate is fixed. the focal plane of the camera can be moved closer to the camera as the potential across the MEMS cell is increased.
In general, the capacitance of a MEM capacitor versus the applied potential is measured individually for each MEM capacitor as a part of the production process. This data is then stored in a memory cell for each individual camera to define the focus range. The associated requirement for expensive off-chip equipment and test time significantly adds to product cost.